Does something need to be done formally to establish a business valuation without a stock offering, and are there any tax consequences of establishing such a valuation?
These alternative valuations can provide you with justifiable options when reporting on tax returns. As for how the value of your equity in the company relates to tax reporting - I can't offer a definitive answer.
The federal securities laws define an accredited investor in Rule 501 of Regulation D as:
5. a natural person who has individual net worth, or joint net worth with the person’s spouse, that exceeds $1 million at the time of the purchase, provided that the value of a person’s primary residence may not be used for such net worth calculation, but any indebtedness in excess of the value of the primary residence shall be used in the calculation;
6. a natural person with income exceeding $200,000 in each of the two most recent years or joint income with a spouse exceeding $300,000 for those years and a reasonable expectation of the same income level in the current year
Your business surely can be considered an asset. The difficulty is in the valuation as you've mentioned. Cash on hand. Multiples of revenues or profits. These are all options.
Not sure what the SEC says on the matter.
The easiest thing to do, if you need to be 100% certain, would be to get a bank loan based on the value of your business and have the cash on hand to prove you meet the requirement.
How would you invest in a startup using your LLC? You can't. You need cash to invest in a startup.
I'm not sure as to how much of your net worth of at least $1MM needs to be cash and how much can be other assets though.